In the field of non-volatile media (NVM), as memory cells are forced closer and closer together to achieve smaller and/or higher capacity products, memory cells have reduced isolation from each other. The reduced isolation increases certain effects. One such effect is disturbance coupling, where accessing one cell (an aggressor) causes artifacts associated with that access to disturb neighboring cells (victims). For media that use an electric or magnetic process to program the state of a memory cell, such as disk drives or flash media, magnetic and/or electric effects propagate to surrounding memory cells. For media that use a thermal process to program the state of a memory cell, such as phase change media, thermal effects propagate to neighboring memory cells. When accessing a memory cell, disturb coupling may result in a change in the state of the surrounding memory cells.
Defect remapping schemes may implement re-vectoring schemes, wherein a logical address associated with a defective physical region is directed to a different physical region. Changing physical regions changes the set of neighbors having proximity disturb relationships to the data stored in the logical address. For example, data may be stored at a logical address mapped several groups of memory cells. If defect remapping changes one of those groups, the set of neighbors associated with the logical address changes. Thus, reads from or writes to the logical address disturb a different set of neighbors before and after remapping. Remapping portions of memory increases the complexity of identifying neighbors and tracking disturbance effects.